1. Field of the Invention
The present invention relates to a recording apparatus including a plurality of sheet feed ports with a shared conveying path and a method of controlling the same.
2. Description of the Related Art
In recent years, there has been remarkable development in so-called “multi-function peripherals” (MFPs) which carry out a copy function, a printer function for printing image data or the like outputted from a personal computer (PC), and a facsimile (hereinafter simply “fax”) function by a single recording apparatus.
MFPs can record images on recording sheets in copy mode, printer mode, and facsimile rode (fax mode). An MFP is normally equipped with a plurality of sheet feed ports for feeding recording sheets. Generally, one out of the plurality of sheet feed ports is a so-called “manual feed port” that enables an operator to select and set a desired type of recording sheet for each image recording, while the other sheet feed ports are so-called “cassette feed ports” in which a comparatively large number of recording sheets are stored.
A construction for an MFP is known in which a conveying path for recording sheets fed from the respective sheet feed ports is shared to reduce the number of sheet feeding rollers for feeding sheets and discharge rollers for discharging sheets, resulting in reduced apparatus size. Reductions in apparatus size are desired since MFPs are often installed in offices with limited space.
With a conventional MFP, while image information transmitted from a personal computer is being recorded in printer mode, for example, it is not possible to record fax image information transmitted by fax. In this case, the received fax image information is stored in an image memory, and when the recording in printer mode is completed, the image information is read out from the image memory and corresponding images are recorded on recording sheets.
As mentioned above, in an MFP where a conveying path is shared by recording sheets fed from the cassette feed ports and recording sheets fed from the manual feed port, when a sheet is manually set in the manual feed port and present on the shared conveying path, it will not be possible to feed a recording sheet (a “cassette-fed recording sheet”) from any of the cassette feed ports.
A communication protocol for fax communication is prescribed that the receiver should inform the transmitter of a sheet size of its recording sheets in advance and the transmitter transmits images in accordance with the sheet size.
Also, since the sheet size of a manually fed recording sheet is set by the operator whenever image recording is carried out, the sheet size does not always match the sizes of the cassette-fed recording sheets.
When a manually fed recording sheet is present on the shared conveying path, since the sheet sizes of the manually fed recording sheet and the cassette-fed recording sheets may not match as mentioned above, even if fax image information is received, it will not be possible to convey a cassette-fed recording sheet from a cassette feed port or to record a received image corresponding to the fax image information onto a cassette-fed recording sheet.
In a conventional MFP, in such situation, the received fax image information is stored in the image memory and the recording of images in fax mode is put on standby until it becomes possible to feed a sheet from a cassette sheet feed port (see Japanese Laid-Open Patent Publication (Kokai) No. H10-200686, for example).
However, when the data size of the received fax image information is larger than the maximum storage capacity of the image memory, the image memory will not be able to store all of the fax image information.
Thus, there is the problem that the MFP will become unable to receive fax image information being transmitted and the reception of the fax image information will be interrupted.